1. Field of the Invention
The present invention relates to an image forming apparatus for separating a transferred material from an image carrier after completing the transfer of a developer image formed on the image carrier on a transferred material and a method for separating and conveying a transferred material.
2. Description of the Related Art
In an electro-photographic image forming apparatus, a peeling device using a sucking device jointly and acting as a sucking device to suck and peel a paper, that is a transfer material, on which a toner image is transferred electrostatically from the surface of a photosensitive drum by generating an air current in the peeling direction so as to assist an electrostatic peeling device such as a peeling charger for peeling a paper electrostatically by a charging device such as a transfer charger is now attracting attention.
As an example of a sucking device to generate an air current in the peeling direction, a device for assisting the peeling of a paper by an air sucking force by connecting a sucking duct to a separation electric charger has been disclosed in Japanese Patent Disclosure (Kokai) No. 222800/1997.
In the case of this type of peeling device using a sucking device jointly, if the conveying characteristic of a paper is bad after peeled off, the image surface of the paper can be rubbed by a paper conveying rib guide, etc. in a conveying path, the quality of a transferred image can be lowered, the paper conveying rib guide can be stained and furthermore, the jamming of a paper may be caused and therefore, it becomes necessary to provide a sufficient sucking wind velocity by an sucking device in order to assure the stabilized conveyance of a paper after peeled off from a photosensitive drum and prevent the paper from turning back to the photosensitive drum.
However, if the sucking velocity of a sucking device is increased to assure the certain peeling, amount of contaminants sucked such as toner and the like floating around a peeling device by the sucking device will increase. If contaminants are adhered to devices around a peeling device such as the surface of a guide supporter that guides a paper to a transferring device or the surface of a rib guide that guides a paper in the direction of a fixing device after peeling and contaminants are accumulated, the reverse side of a paper being conveyed on the surface of the conveying guide becomes dirty, and the quality of an image transferred on the paper is lowered.
Accordingly, for a peeling device using an electrostatic peeling device and an sucking device jointly, it is demanded to peel off a paper certainly from a photosensitive drum by the sucking force of the sucking device and convey the peeled paper stably and the peeling device is demanded to be capable of reducing amount of contaminants floating around the peeling device and sucked by an sucking device as could as possible and preventing a paper from becoming dirty.